I have never used regular expressions. I have an immediate requirement that requires use of regular expressions. I have a set of macros, say $F, $R, $T, and $#1 to $#9. I have a text box which could accept any set of alphabetes, numbers, and/or one or more of the above-mentioned macros.

I have a function where I validate the text box content. How do I specify that if a $ only certain characters could be allowed as the next character?